Unionist politicians last night slammed an RTE decision to broadcast an interview with killer Brendan McConville that was recorded via a phone call to Maghaberry Prison.

The interview with McConville, one of two men convicted of the murder of PSNI officer Stephen Carroll in 2009, is to be broadcast by RTE Raidio na Gaeltachta this morning.

In the interview, McConville claims he is innocent of the crime, and says the case against himself and his co-accused John Paul Wootton is flawed.

Former Sinn Fein councillor McConville from Craigavon and 25-year-old Wootton from Lurgan were convicted in 2012 for their part in the murder of Constable Carroll.

Both were ordered to serve a minimum of 25 and 14 years respectively in jail.

Constable Carroll (48), from Banbridge, Co Down, was the first PSNI officer to be killed by terrorists.

He was shot dead after police were lured to a callout in Lismore Manor in Craigavon on March 9, 2009.

The Continuity IRA claimed responsibility for the murder.

Ulster Unionist MLA Doug Beattie said he was "astounded" that the republic's state broadcaster had decided to put on air a convicted murderer.

And he queried how the interview was arranged.

"It's incredible that a man who has been found guilty of murder and sentenced now has free and open access to the media in another jurisdiction to push his agenda," he said.

"Would they broadcast an interview with a drug dealer or a paedophile?"

The UUP MLA also said there were serious questions to be answered by the Department of Justice.

"If this man is able to conduct a media interview from a phone inside the prison, who else has he been able to reach?" he said.

"This is a serious security issue, and I will be writing to Ronnie Armour, head of the NI Prison Service, asking him to look into this as a matter of urgency."

It's understood that the Department of Justice had not been told the interview was taking place, and had not been approached by RTE seeking permission to conduct the interview for broadcast.

The Department for Justice last night issued a statement saying only: "We do not comment on individual prisoners."

DUP MLA Paul Frew also hit out at RTE for giving McConville a platform: "What strikes me is how irresponsible RTE have been in this matter.

"Put it like this: if this was a brave Garda responding to a 999 call who had been brutally murdered, would RTE be broadcasting an interview with his killer?

"I don't think so."

Mr Frew said the McConville interview would also be very hurtful to Stephen Carroll's relatives.

"I think RTE have been completely irresponsible," he added.

The MLA said he was concerned at the potential implications if every prisoner was able to record interviews with the media when they wished.

"This is a very serious matter which the NI Prison Service and the Department of Justice have to address."

Responding to the MLA's criticism, an RTE spokeswoman said last night: "The RTE Raidio na Gaeltachta interview with Brendan McConville was carried out in light of his case currently being under review by the Criminal Cases Review Commission (CCRC).

"The interview was arranged via an intermediary involved in the campaign for a review of Brendan's case.

"It was conducted by telephone and deals exclusively with the case review.

"The programme includes a statement received from the CCRC as to the latest information on the review."

The interview was broadcast on An tSeachtain le Mairin Ni Ghadhra on RTE Raidio na Gaeltachta on Saturday morning at 10am.